package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.RedisData;
import com.hmdp.dto.Result;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Shop;
import com.hmdp.mapper.ShopMapper;
import com.hmdp.service.IShopService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.CacheClient;
import com.hmdp.utils.SystemConstants;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.geo.Distance;
import org.springframework.data.geo.GeoResult;
import org.springframework.data.geo.GeoResults;
import org.springframework.data.redis.connection.RedisGeoCommands;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.domain.geo.GeoReference;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.StringUtils;

import java.time.LocalDateTime;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import static com.hmdp.utils.RedisConstants.*;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopServiceImpl extends ServiceImpl<ShopMapper, Shop> implements IShopService {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private CacheClient cacheClient;

    @Override
    public Result queryById(Long id) {
        System.out.println("查询店铺");

        //解决缓存穿透
        /*Shop shop = cacheClient
                .queryWithPassThrough(CACHE_SHOP_KEY, id, Shop.class, this::getById, CACHE_SHOP_TTL, TimeUnit.MINUTES);
      */  //互斥锁解决缓存击穿

        //逻辑过期解决缓存击穿
//        Shop shop = queryWithLogicalExpire(id);
        Shop shop = cacheClient
                .queryWithLogicalExpire(CACHE_SHOP_KEY,id,Shop.class,this::getById,20L,TimeUnit.SECONDS);

        if (shop == null) {
            return Result.fail("没有该商铺的信息");
        }

        return Result.ok(shop);

    }

    /*private static final ExecutorService CACHE_REBUILD_EXECUTOR = Executors.newFixedThreadPool(10);

    public Shop queryWithLogicalExpire(Long id) {
        String key = CACHE_SHOP_KEY + id;
        String shopStr = stringRedisTemplate.opsForValue().get(key);
        if (StringUtils.isEmpty(shopStr)) {
            return null;
        }
        //判断是否命中空值
        RedisData redisData = JSONUtil.toBean(shopStr, RedisData.class);
        Shop shop = JSONUtil.toBean((JSONObject) redisData.getData(), Shop.class);
        LocalDateTime expireTime = redisData.getExpireTime();
        if (expireTime.isAfter(LocalDateTime.now())) {
            return shop;
        }

        boolean lock = lock(LOCK_SHOP_KEY + id);

        if (lock) {
            CACHE_REBUILD_EXECUTOR.submit(() -> {
                try {
                    this.saveShop2Redis(id, 20L);
                } catch (Exception e) {
                    throw new RuntimeException(e);
                } finally {
                    unlock(LOCK_SHOP_KEY + id);
                }
            });

        }

        return shop;
    }*/

    /*public Shop queryWithMutex(Long id){
        String key=CACHE_SHOP_KEY+id;
        String shopStr = stringRedisTemplate.opsForValue().get(key);
        if(!StringUtils.isEmpty(shopStr)){
            Shop shop = JSONUtil.toBean(shopStr, Shop.class);
            return shop;
        }
        //判断是否命中空值
        if(shopStr !=null){
            return null;
        }

        Shop shop = null;
        try {
            boolean lock = lock(LOCK_SHOP_KEY + id);

            if(!lock){
                Thread.sleep(50);
                return queryWithMutex(id);
            }

            Thread.sleep(200);
            shop = getById(id);
            if(shop==null){
                stringRedisTemplate.opsForValue().set(key,"",CACHE_NULL_TTL, TimeUnit.MINUTES);
                return null;
            }

            Random r=new Random();
            long extraTTL=r.nextInt(6);

            stringRedisTemplate.opsForValue().set(key,JSONUtil.toJsonStr(shop),CACHE_SHOP_TTL+extraTTL, TimeUnit.MINUTES);
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }finally {
            unlock(LOCK_SHOP_KEY+id);
        }

        return shop;
    }*/

    /*public boolean lock(String key) {
        Boolean flag = stringRedisTemplate.opsForValue().setIfAbsent(key, "1", LOCK_SHOP_TTL, TimeUnit.SECONDS);
        return BooleanUtil.isTrue(flag);

    }

    private void unlock(String key) {
        stringRedisTemplate.delete(key);

    }

    public void saveShop2Redis(Long id, Long expireSeconds) throws InterruptedException {
        Thread.sleep(200L);
        Shop shop = getById(id);

        RedisData redisData = new RedisData();
        redisData.setData(shop);
        redisData.setExpireTime(LocalDateTime.now().plusSeconds(expireSeconds));

        stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY + id, JSONUtil.toJsonStr(redisData));
    }
*/
    @Override
    @Transactional
    public Result update(Shop shop) {
        Long id = shop.getId();
        if (id == null) {
            return Result.fail("店铺id不能为空");
        }
        updateById(shop);

        stringRedisTemplate.delete(CACHE_SHOP_KEY + id);
        return null;
    }

    @Override
    public Result queryShopByType(Integer typeId, Integer current, Double x, Double y) {

        if(x==null||y==null){
            // 根据类型分页查询
            Page<Shop> page = query()
                    .eq("type_id", typeId)
                    .page(new Page<>(current, SystemConstants.DEFAULT_PAGE_SIZE));
            // 返回数据
            return Result.ok(page.getRecords());
        }

        int from =(current-1) * SystemConstants.DEFAULT_PAGE_SIZE;
        int end = current * SystemConstants.DEFAULT_PAGE_SIZE;

        String key=SHOP_GEO_KEY+typeId;
        GeoResults<RedisGeoCommands.GeoLocation<String>> results = stringRedisTemplate.opsForGeo()
                .search(key,
                        GeoReference.fromCoordinate(x, y),
                        new Distance(5000),
                        RedisGeoCommands.GeoSearchCommandArgs.newGeoSearchArgs().includeDistance().limit(end)
                );
        if (results == null) {
            return Result.ok(Collections.emptyList());
        }


        List<GeoResult<RedisGeoCommands.GeoLocation<String>>> list = results.getContent();
        if(list.size()<=from){
            return Result.ok(Collections.emptyList());
        }
        List<Long> ids =new ArrayList<>(list.size());
        Map<String,Distance> distanceMap=new HashMap<>(list.size());

        list.stream().skip(from).forEach(result->{
            String shopIdStr = result.getContent().getName();
            ids.add(Long.valueOf(shopIdStr));

            Distance distance=result.getDistance();
            distanceMap.put(shopIdStr,distance);
        });

        String idStr = StrUtil.join(",", ids);

        List<Shop> shops = query().in("id", ids).last("order by field(id," + idStr + ")").list();
        for (Shop shop : shops) {
            shop.setDistance(distanceMap.get(shop.getId().toString()).getValue());
        }

        return Result.ok(shops);
    }
}
